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the northeast corner of Main street and the street fronting the river, in West Newton. The block is 18 inches high, horizontal section 14 by 8 inches, top face 12 by 6 inches, B. M. on top face. This bench being the starting-point of levels, its reference was arbitrarily assumed at 250.0. All references in this survey are in feet.

No. 2. A cross cut on the sixteenth stone from the water-front, seventh course from the top, north side of the east abutment of the West Newton bridge. Reference 248,157.

No. 3. A cross cut on the eighth stone from the water-front, twelfth course from the top, north side of the east abutment of the West Newton bridge. Reference 240,209.

No. 4. A cross cut, with a figure 4 alongside, on a large flat stone, about two miles below West Newton, on right bank. The stove is a little to the left of a line through the chimney of a paper-mill at West Newton, tangent to the left bank of the river. The stone is 20 by 9.5 feet, cross is 0.22 foot square, figure 4 is 0.26 foot long. Reference 224,245.

No. 5. A cross cut on the northwest corner of the top foundation-course of the east abutment of the railroad-bridge crossing Sewickly Creek, near its month, may be known by a large V cut near the northeast angle of the cross. Reference 225,030.

No. 6. A cross cut on a large stone directly across the river from Suter's Pier, at Sutersville. Reference 221,196. This B. M. is very badly cut, on account of the nature of the stone, which, being slaty in its character, would not work well under the chisel.

No. 7. A cross cut on a large piece of conglomerate, irregular in shape and reddish in color. It is situated on the left bank of the river, about 800 yards below the old slackwater dam at Buena Vista. Reference 214,908.

No. 8. A double cross (+) ent on a large out-cropping bowlder on the left bank of the river, a little below Robbins's Rw. The point of rest for the rod is at the cross nearest the channel. Reference 206,453.

No. 9. A cross cut near the top of a large stone on the left bank of the river. Above the cross is an are of nine small holes drilled into the stone, which is situated midway between the Alps House (a large hotel at Alpsville, on the right bank) and the Coultersville Baptist church, a very prominent frame building, with long windows, standing near the southwest end of Alpsville. Reference 211.291.

No. 10. A cross, surmounted by a letter X, on a flat stone lying on the right bank, bet ween the coal-tipples of N. J. Bigley and Brown & Cochran. Reference 200,863.

No. 11. No description will be here given, as it has since been destroyed.

No. 12. A cross cut on a large stone on the left bank of the river, almost in the prolongation of Sixth street, Mekeesport. Reference 206,309.

The above description will, I think, be sufficient to enable any one to determine the location of any of the benches without difficulty.

In determiniug the difference of level betwoen the water-surface at West Newton and at Mckeesport, the rule was adopted to repeat on the morning of each day the work done on the preceding afternoon. After reaching the end of the work, it was gone over twice from end to end, continuously, for the purpose of checking. On account of · ny having been laid up sick, the final leveling was done by Mr. Hoag, and our work agreed within five-hundredths of a foot. The difference of level found was 25.427 feet. From this subtract 1.1 feet, the depth of water at the bridge, and we obtain 24.3 feet as the difference of level between the Monongahela pool and the bottom of the river at West Newton. A depth of 6 feet at West Newton would give the water-surface 30.3 feet above the Monongahela pool. This can be divided into three pools, requiring a lift of 10 feet to pass from pool to pool. The remaining 0.3 could be removed by dredging.

Owing to the low stage of water, the bottom of the river was distinctly visible for almost the entire distance from West Newton to Alpsville. The surface of the bottom is formed of gravel, except in a bend just above Sutersville and below the old dams, in which localities the surface-stratum was found to be of sand. As we were unprovided with the necessary boring-tools, we were unable to determine what formation underlay the bottom. This is a question that must be carefully investigated before any final locations for the locks and dams can be decided on.

The discharge of the river was determined by Mr. Hoag at Rattle's Ripple. He made use of surface-floats over a course of 40 feet in length, the average depth of the section being one foot. The amount of discharge he found to be 183 cubic feet per second, which will give 10,980 per minute, or 658,800 per hour. Now, the size of lock proposed for use in this work is that of the large locks on the Monongahela. The chambers of these locks measure 250 feet in length by 56 in breadth. These dimensions, with a list of 10 feet, give 140,000 feet as the amount of water required for one lockage. About twenty minutes is needed for a boat to pass one of these locks, or three boats can pass in an hour, requiring 420,000 cubic feet of water in the same time, and leaving a surplus of 238,800, or 12 of a prism of lift. Now, when the river was ganged, althongli it was very low, it was not at its lowest stage, aud, judging by information furnished me by the inhabitants in conversation, I am inclined to ihink that the supply in a dry season must be so scant that it would hardly be sufficient. On this point, however, it was impossible to obtain reliable data, as the people living near the river do not seem to study its movements with any care. Granting, however, that this supply (183 cubic

feet per second) can be kept up, it will be casily seen that the water must be carefully husbanded, and that a clam of the very brst design to prevent leakage will be required, and that the foundation for the lock must be maile very tight, in order that the water may not escape through it.

To form three pools three dams will be reqnired. As the exact location of each dam has not been determined on, I have only been able to assume a length for each one. Taking that point on each pool where there will be 6 feet of water, and measuring the distance from the top of the bank on one side to the top of the bank on the other, we find the sum of the three distances to be 1,250 feet, which, deducting $5 feet for width of lock, gives the total length of the three dams of 1,595 feet, or an average leugth of 532 feet for each dam.

These dams I propose to construct as follows: 1st. To build strong timber cribs, about 6 feet in height and 50 feet in width, and place them in line across the stream. 21. To drive a row of heavy sqnare piles along the down-stream side of the cribs, for the purpose of keeping them in position, the tops of the piles to be flush with the upper surface of the cribs. 3d. To drive on the up-stream side of these cribs two rows of 8-inch sheeting-piles in juxtaposition, the rows to break joints. These piles to be driven so that their tops shall be flush with the top surfaces of the foundation-cribs, the up-stream row of sheeting-piles to support the lower ends of the timbers composing the apron of the dam. 4th. To build a strong crib on top of these foundation-cribs, and make it a continuous structure from one end of the dam to the other. This supercrib to be 10 feet in height, the down-stream side being built in three steps of 34 feet each, the up-stream side being an apron formed of heavy timbers, wrought to true faces, and laid as close together as possible. The apron to have a slope of 1 perpendicular to 2.5 base. 5th. The crest of the dam will be formed by a timber 12 by 18, thoroughly bolted and fastened to the crib-work. 6th. To till in all the crib-work with riprap. 7th. To cover the entire up-stream side of the dam from the top of the apron down with gravel, the top surface of which is to have a slope of 1 perpendicular to 6 base.

ESTIMATE FOR ONE DAM 532 FEET IN LENGTII. 14,167 linear feet of piles, 12 cents per foot

$1,770 87 90,720 feet (board-measure) sheet-piles, at 35 cents per M

3, 175 20 848,100 feet (board-measure) tiviber in crib-work, at $35 per M

29, 694 00 1:27,000 feet (board-measure) timber in apron, at $35 per M

4, 115 00 5:32 piles, driving, at $2.50 each..

1.330 00 1,064 sheeting-piles, driving, at $2.50 each

2,6.) 00 11,000 cubic yards riprap, at $1.25 per yard

13, 750 00 10,585 cubic yards gravel, at 10 cents per yard

4,235 20 Total cost of dam..

61, 060 27 MASONRY ABUTMENT. At the end of the dam opposite the lock will be an abutment of stone, extending 30 feet above and below the dam, with wing-walls 40 feet in length. The abutment is to be 5 feet thick at the top and 10.5 feet thick at the bottom, the side next the bank to be vertical, the height 2:2 feet. It is to rest on a foundation of piles in four equidistant rows parallel to the face of the abutment, the piles in each row to be 5 feet apart. A capping-piece 12 by 12 incbes will be laid on each row of piles, and the grillage thus formed covered by a platform of 5-inch plank laid crosswise upon it. The top of the platform to be laid on a level with the bottom of the foundation-crib of the dam. On this platform will be built the abutment.

ESTIMATE FOR ABUTMENT. 3,010 linear feet of piles, at 124 cents per foot

$380 00 9,120 feet (board-measure) grillage, at $35 per M..

319 20 9,975 feet (board-measure) platform, at $35 per M.

319 13 4:38 cnbic yards quarry-face masonry, at $9.60..

4, 204 80 6:36 cubic yards rubble masonry, at $7.20.

4,579 20 5,000 cubic yards riprap for protecting bauks, at $1.25

6, 250 00 152 piles, driving, at $2.50 each

380 00 Laying grillage

33 00 Laying platform...

70 00

Total for abutment....

16, 565 33 The foundation adopted for the lock is similar to that of the lock recently built at Henry, on the Illinois River, the bed in each case being permeable soil. In this case, however, additional precautions have been taken to guard against leakage on account of the scantiness of the water-supply.

Before going farther it may be well to give a brief description of the Henry lock.

This lock is built entirely in the bed of the river, the center line at the head being 350 feet from the low-water line, and at the foot 150 feet. The earth where the foundition is placed was first removed to a depth of 6 feet. Three thousand two hundred bearing piles 12 inches in diameter were driven so as to have tive rows under the entire length of each wall, the piles in each row being 3 feet apart, the remainder of the piles being driven over the chamber space in seven parallel rows, the piles in these rows being also 3 feet apart. Under the head-bay the longitudinal rows are doubled, being fifteen in number. Longitudinal foundation timbers 12 inches square were then placed on these piles and securely bolted to them. Cross-timbers 12 inches square were then laid on these and securely bolted to them, forming a grillage. The spaces between the timbers, and to a depth of 3 inches below, were tilled with concrete, thus making a depth of concrete of 27 inches. All the foundation was then covered with 24-inch plauk. Six rows of sbeeting-piles were driven across the foundation, the piles being from 4 to 6 feet in length.

The additions I propose to make to the above are, to increase the depth of concrete to 36 inches; to put in ten rows of sheeting piles-instead of six; to put at the head of the lock two rows of sheeting piles, 8 feet apart, instead of one, and to fill in the intermediate space with 6 feet depth of concrete; all the sheeting-piles to be 10 feet long instead of 4 to 6 feet.

As the lock here proposed is smaller than the Henry lock, the chamber of which is 250 feet by 75, the number of piles will be reduced from 3,200 to 2,309.

ESTIMATE FOR FOUNDATION OF LOCK 250 FEET LONG BY 56 FEET WIDE. 46,180 linear feet of piles, at 124 cents per foot.

$5,772 50 173,410 feet (board-measure) sheeting-piles, at $35 per M.

6, 070 40 42,600 feet (board-measure) sheeting-piles, at $35 per M..

1, 470 00 135,000 feet (board-measure) lower-flooring course, at $35 per M.

4,375 00 51,050 feet (board-measure) upper-flooring course, at $35 per M.

1,786 75 8,400 feet (board-measure) binling-strips at $35 per M.

294 00 1,100 cubic yards of concrete, at $6 per yard...

6, 600 00 7,000 cubic yards of earth excavation, at $1 per yard.

7,000 00 2,309 piles, driving, at $2.50 each..

5,772 50 1,050 sheet piles, driving, at $2.50 each

2,625 00 Laying grillage

550 00 Laying flooring

1,000 00

Total cost of foundation

43, 316 15

The lock is to be of stone. Dimensions of chamber, 250 by 56 feet; lift, 10 feet; walls, 22.5 feet high, 10 feet thick at top, 13.5 feet thick at bottom; 350 feet total length.

ESTIMATE FOR LOCK. 2,000 cubic yards cut-stone masonry, at $14.40 per yard..

$29, 800 00 1.200 cubic yards quarry-face masonry, at $9.60 per yard.

11,520 00 3,5713 cubic yards rubble masonry, at $7.20 per yard..

25, 293 60 4,000 cubic yards earth filling, at 50 cents per yard

2,000 00 1 lift-wall, 167 cubic yarıls quarry-face masonry, at $9.60 per yard.

1,003 20 4 gates, complete, at $4,000 each..

16, 000 00

[blocks in formation]

618, 475 65

3 locks and dams, at $206,158.55 each.
Removing obstacles already existing, as old locks and dams, old bowlder,

dams, &c

7,000 00

625, 475 65 62, 547 56

Add 10 per cent. for contingencies

Total cost of improvements.

608, 023 21

This estimate will carry the full depth of water (6 feet) to the lower end of the town of West Newton. It is possible that a little dredging may be needed near Buena Vista, but it will be small in amount, and as the construction of the dams mentioned might cause the removal of this bar in order to secure a supply of gravel, no account bas been taken of it in the estimate.

MOVABLE DAMS.

Another mode of improvement, by means of movable dams, is presented.

The system proposed is the same as that adopted at Port-à-l'Anglais, on the Upper Seine.

The dam on the Youghiogheny will be somewhat longer than at Port-à-l'Anglais, the former being 532 feet and the latter 446.

The movable dam proposed consists of Chanoine wickets, erected in a free pass and on a weir, the pass-wickets being 13 feet high and the weir-wickets 7 feet. The depth of water required at the head of each pool is 6 feet; consequently, we will have a lift of 7 feet from pool to pool.

The pass is assumed at 150 feet in width, requiring thirty-eight wickets, and ninetyfive will be required for the remaining 382 feet, which will constitute the weir, the wickets being taken as 4 feet wide.

The use of movable dans reduces the lift of the locks from 10 to 7 feet.

As the total elevation required to give 6 feet of water at West Newton is 30 feet, it is evident that tive movable dams will give 35 feet of elevation, or five feet more than is necessary, while four dams will give but 28 feet, or 2 feet less than is needed. If, therefore, the slack-water is to stop at West Newton bridge, we must have either five dams of 6 feet lift or four dams of 7.50 feet lift each). I should recommend the latter. If, however, the slack-water is to be extended indefinitely above West Newton, I would recommend the construction of five dams with 7 feet lift, believing these dimensious to be the best for general use. The estimates that follow are for movable dams having the last-named lift. The comparison of cost is, therefore, somewhat unjust to the latter system, as it actually gives 5 feet more elevation than the former.

ESTIMATE OF COST. For a movable dam, constructed like that across the Upper Seine at Port-à-l'Anglais, height of wickets, 13 feet; liit of locks, 7 feet; breadth of wickets, 4 feet :

NAVIGABLE PASS.

$50 69 79 20

3 91 43 80

2 24 52 50

Cost of foundation por running foot. 3.52 cubic yards cut-stone masonry, at $14.40.. 11 cubic yards rubble masonry, at $7.20.. 3.13 cubic yards ri prap, at $1.25 7.30 cubic yards concrete, at $6. 64 feet (board-measure) of sill, at $35 per M.. 1,500 feet (board-measure) piles, & c., for coffer-dam, at $35 per M Total cost per running foot....

Cost of trestle of pass. 1 trestle, 1,300 pounds, at 10 cents.. 2 journal-boxes, 130 pounds, at 7 cents 2 anchoring-rods, 133 pounds, at 10 cents. 1 anchoring-disk, 80 pounds, at 7 cents. 2 claw-balks, 120 pounds, at 10 cents. 1 hand-rail post, 12 pounds, at 10 cents.

232 34

$130 00

9 10 13 30

5 60 12 00 1 20

[blocks in formation]

Cost of the sole. 1 heurter and slide, 480 pounds, at 10 cents 1 tripping-rod, 98 pounds, at 10 cents. 2 guides, 42 pounds, at 10 cents. 1 roller, 26 pounds, bronze, at 40 cents.

$18 00

9 80 4 20 10 40

Cost of sole and appurtenances

72 40

Total cost of one section 4 feet wide of the pass, excluding the foundation.
Trestle, complete
Wicket, complete..
Sole and appurtenances.
Chains, bolts, &c., not considered in the above..

$171 20 154 80 72 40 50 00

Total cost of one section...

448 40

Or, per running foot.
Cost of foundation, per running foot.

$112 10 232 34

Cost of pass, per running foot

344 44 Cost of pass, 150 feet wide, $51,666.

WEIR.

Cost of foundation of weir, per running foot. 1.10 cubic yards cut stone, at $14.40..

$15 84 2.50 cubic yards rubble, at $7.20

18 00 3.70 cubic yards riprap, at $1.25

4 63 5.50 cubic yards concrete, at $6..

33 00 64 feet (board-measure) of sills, at $35 per M.

2 24 2,000 feet (board-measure) piling, &c., at $35 per M.

70 00 Total cost per running foot.

143 71 Cost of trestle and wicket of the weir. There being no data of the weights and dimensions of the wickets of the weir, I assumed that, as they are about three-fourths as high as the wickets of the pass, they would probably cost about three-fourths as much. Those of the pass (including the trestles) cost $112 per running foot. hence those of the weir should cost per running foot about..

$84 00 To this add the cost of foundation per ruuning foot...

143 71 Cost of weir, per running foot....

227 71 Cost of weir, 382 feet long, $36, 985.22.

Cost of pass and weir. Cost of weir 382 feet long

86,985 22 Cost of pass 150 feet long.

51, 666 00 Total cost.....

138, 651 22 If a maneuvering-boat be used for the weir, we can omit the trestle bridge above the wickets. This would effect a saving of 95 trestles, which, at an average cost of $128, would amount to $12,160. From this we must take the cost of the boat, which will be about $300, leaving a total saving of $11,860. The suppression of the wickets would also greatly reduce the cost of the foundation of the weir, as the latter would not then be so wide. Assuming that this would reduce the cost of foundation by onethird, we bave a saving from this source of $18 per running foot, or of $18,336 in the length of the weir.

Under this condition, the total diminution of cost would beOn the foundation...

$18, 3:36 00 On the trestles

11, 860 00

Or, in all......
Subtracting this from the cost before given, which is..

30, 196 00 138, 051 22

We obtain as the cost when the boat is used..

108, 455 22

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